Conventionally, among this kind of light emitting diodes of wavelength conversion type are known the one shown in FIG. 22 (Japanese Patent No. 2900928) and the one shown in FIG. 23 (Japanese Patent Laid-Open Publication No. Hei 7-99345). The former one is a light emitting diode 1 of lead frame type, having a structure in which: a recess 3 is arranged in a metal stem 2, one of the lead frames; a light emitting diode element 4 made of gallium nitride type compound semiconductor is placed on and fixed to this recess 3; and this light emitting diode element 4 is connected with the aforementioned metal stem 2 and a metal post 5, the other lead frame, by using bonding wires 6 and 7, respectively; the whole being sealed by a transparent resin 9 of bombshell form. A fluorescent material 8 for wavelength conversion is dispersed into the transparent resin 9 mentioned above. When the light emitting diode 1 is lit, the light emitted from the light emitting diode element 4 impinges the fluorescent substance 8 and is converted into yellow so that it can blend with the original blue luminescence from the light emitting diode element 4 to present white in luminescent color.
Then, in the latter one, a light emitting diode element 4 for blue luminescence, made of gallium nitride type compound semiconductor is placed on and fixed to a recess 3 in the above-mentioned metal stem 2, and a fluorescent material containing resin 8 is filled into the above-mentioned recess 3 so as to cover the top of this light emitting diode element 4. Accordingly, in the light emitting diode 1 having such a configuration, the blue luminescence emitted from the light emitting diode element 4 excites the fluorescent material in the fluorescent material containing resin 8, and the light converted thus in wavelength blends with the original blue luminescence from the light emitting diode element 4 to come out as white luminescence.
Nevertheless, among the conventional light emitting diodes 1 described above, the former had the problem that since that fluorescent material 8 is dispersed into the transparent resin 9 which seals the light emitting diode element 4, the light passing through the transparent resin 9 drops in transmittance, decreasing the intensity of the white luminescence. It also had the problem that the fluorescent material 8 is higher than the transparent resin 9 in specific gravity and thus is difficult to disperse uniformly, causing chromaticity variations not only between different light emitting diodes but also within a single light emitting diode.
On the other hand, the latter had the problem that since the fluorescent material containing resin 8 covers the vicinity of the top of the light emitting diode element 4, the transmission of the light from the light emitting diode element 4 is hampered by the fluorescent material so that white luminescence of high intensity cannot be obtained.
It is thus an object of the present invention to provde a light emitting diode improved in the intensity of white luminescence and suppressed in chromaticity variations.